ES2871999T3 - Aerosol generation procedure - Google Patents

Abstract

A method of generating aerosol from an aerosol generating substrate (200) using an aerosol generating device with at least one heat source (102, 104) arranged to heat, but not burn, the aerosol generating substrate (200 ) In use; wherein the aerosol generating substrate (200) comprises first and second portions (202, 204) having substantially the same composition, and / or wherein the aerosol generating substrate (200) comprises first and second portions (202, 204) and there is no physical separation between the portions; The method comprising the steps of: heating the aerosol-generating substrate (200) in the aerosol-generating device for a period of time corresponding to one session of use, so that a temperature profile of the first portion (202) of the substrate aerosol generator (200) during heating is different from a temperature profile of the second portion (204) of the aerosol generator substrate (200); characterized in that during a first part of the session, the first portion (202) of the aerosol generating substrate (200) reaches a prescribed operating temperature and remains at that temperature for an extended period, and the second portion (204) reaches a first temperature that is lower than the temperature of the first portion (202), with the first portion (202) reaching the prescribed operating temperature faster than the second portion (204) reaching the first temperature; During a second part of the session, the second portion (204) is raised to a second prescribed temperature and remains at that temperature for an extended period; and during one third of the session, the second portion (204) is raised to a third prescribed temperature and remains at that temperature for an extended period, the third temperature being an operating temperature.

Description

DESCRIPTION

Aerosol generation procedure

Technical field

The present invention relates to an aerosol generating device and to an aerosol generating method using the aerosol generating device.

Background

Items such as cigarettes, cigars, and the like burn tobacco during use to create tobacco smoke. Attempts have been made to provide alternatives to these types of items, which burn tobacco, by creating products that release compounds without burning. An apparatus is known which heats the smokable material to volatilize at least one component of the smokable material, typically to form an aerosol that can be inhaled, without burning or igniting the smokable material. Such an apparatus is sometimes described as a "heating without burning" apparatus or a "tobacco warming product" (THP) or "tobacco warming device" or the like. Several different arrangements are known for volatilizing at least one component of the smokable material.

The material can be, for example, tobacco or other non-tobacco products or a blend, such as a blend blend, which may or may not contain nicotine. Documents WO 2013/131764, EP 0 438 862, WO 2015/062983, WO 2016/005533, WO 2015/071682 disclose devices comprising a plurality of heaters.

Summary

The invention is defined in the appended claims.

In its most general form, the present invention provides a method of generating aerosol from an aerosol generating substrate using an aerosol generating device, in which portions of the aerosol generating substrate have different temperature profiles.

Other features and advantages of the invention will be apparent from the following description of preferred embodiments of the invention, given by way of example only, made with reference to the accompanying drawings.

Brief description of the drawings

Figure 1 is a schematic diagram of an aerosol generating device according to an embodiment of the present invention, showing a cross section of the heating chamber with the aerosol generating substrate disposed therein.

Figure 2 is a graph relating to an embodiment in accordance with the present invention, showing programmed heating profiles of two heat sources in an aerosol generating device while heating an aerosol generating substrate.

Figure 3 is a graph relating to an embodiment in accordance with the present invention, showing temperature profiles of two portions of an aerosol generating substrate while being heated by two heat sources in an aerosol generating device.

Detailed description

As used herein, "the" may be used to mean "the" or "the or each" as appropriate. In particular, the characteristics described in relation to "the at least one heat source" may be applicable to the first, second or more heat sources when present. Furthermore, the characteristics described with respect to a "first" or "second" heat source may be equally applicable to the other heat source in different embodiments.

As used herein, the term "aerosol generating substrate" refers to material that provides components that are volatilized upon heating, in the form of an aerosol. In some embodiments, the aerosol generating substrate may comprise a tobacco component, wherein the tobacco component is any material comprising tobacco or derivatives thereof. The tobacco component may comprise one or more of ground tobacco, tobacco fiber, cut tobacco, extruded tobacco, tobacco stem, reconstituted tobacco, and / or tobacco extract. In some embodiments, the aerosol generating substrate may comprise a tobacco substitute.

An aerosol generating device refers to any apparatus that generates an aerosol from an aerosol generating substrate when in use. In particular, an apparatus is known which heats an aerosol generating substrate to form an aerosol that can be inhaled, without burning or igniting the aerosol generating substrate. Such an apparatus is sometimes described as a "heating without burning" apparatus or a "tobacco heating product" or "tobacco heating device" or the like.

Similarly, there are also so-called electronic cigarette devices, which typically vaporize an aerosol-generating substrate in the form of a liquid, which may or may not contain nicotine. However, the aerosol generating device contemplated herein provides an aerosol or vapor by heating an aerosol generating substrate in the form of a solid. In a particular embodiment, the aerosol generating device is a tobacco heating product.

An aerosol generating device for use in the present invention is typically generally elongated. The device has a first or proximal or buccal end and a second or distal end. In use, the user will inhale the aerosol formed by the mouth end of the aerosol generating device. The buccal end can be an open end.

The solid aerosol generating substrate may be of any shape suitable for use with an aerosol generating device. The aerosol generating substrate may be in the form of, or provided as part of, a cartridge or cassette or wand that can be inserted into the apparatus. In some embodiments, the aerosol generating substrate is an elongated rod. In particular, the aerosol generating substrate can be an elongated rod comprising a tobacco component.

The aerosol generating substrate may comprise a plurality of portions. A "portion", as used in this context, refers to a particular spatial part of the aerosol generating substrate. There may be a physical separation between these portions or, more usually, there may be no physical separation between these portions: that is, a portion of the aerosol generating substrate may simply refer to a particular spatial part of a unitary entire substrate. The portions of the aerosol generating substrate need not be the same size as each other.

The aerosol generating substrate may comprise two portions: a first and a second portion. In one embodiment, the aerosol generating substrate comprises first and second portions, wherein the aerosol generating substrate is a unitary body. That is, the aerosol generating substrate is a continuous body in which there is no physical separation between the first and second portions, which may or may not have the same composition throughout.

The first and second portions of the aerosol generating substrate can have substantially the same composition. In some embodiments, the aerosol generating substrate may consist of first and second portions, wherein the first and second portions have substantially the same composition, such that the aerosol generating substrate consists of that composition. When there are a plurality of aerosol generating substrate portions, any number of the substrate portions can have substantially the same composition. In a particular example, all portions of the substrate have substantially the same composition. In one embodiment, the aerosol generating substrate is a unitary continuous body and there is no physical separation between the first and second portions, and the first and second portions have substantially the same composition.

In another embodiment, the first and second portions of the aerosol generating substrate comprise different components; that is, they do not have substantially the same composition. In particular, in embodiments where the aerosol generating substrate is a unitary continuous body and there is no physical separation between the first and second portions, the first and second portions may comprise different components. The aerosol generating substrate can comprise more than two portions. For example, the aerosol generating substrate may comprise three, four, five, or more than five portions.

In a particular embodiment, the aerosol generating substrate can comprise one or more tobacco components, fillers, binders and aerosol generating agents.

The filler component can be any suitable inorganic filler material. Suitable inorganic fillers include, but are not limited to: calcium carbonate (i.e. chalk), perlite, vermiculite, diatomaceous earth, colloidal silica, magnesium oxide, magnesium sulfate, magnesium carbonate, and suitable inorganic absorbents. , such as molecular sieves. Calcium carbonate is particularly suitable. In some cases, the filler comprises an organic material such as pulp, cellulose, and cellulose derivatives. The binder can be any suitable binder. In some embodiments, the binder comprises one or more of an alginate, celluloses or modified celluloses, polysaccharides, starches or modified starches, and natural gums.

Suitable binders include, but are not limited to: alginate salts comprising any suitable cation, such as sodium alginate, calcium alginate, and potassium alginate; celluloses or modified celluloses, such as hydroxypropyl cellulose and carboxymethyl cellulose; starches or modified starches; polysaccharides such as pectin salts comprising any suitable cation, such as sodium, potassium, calcium or magnesium pectate; xanthan gum, guar gum, and any other suitable natural gum.

A binder can be included in the aerosol generating substrate in any suitable amount and concentration.

The "aerosol generating agent" is an agent that promotes the generation of an aerosol. An aerosol generating agent can promote the generation of an aerosol by promoting initial vaporization and / or condensation of a gas to an inhalable solid and / or liquid aerosol. In some embodiments, an aerosol generating agent can enhance the delivery of flavor from the aerosol generating substrate.

In general, any suitable aerosol generating agent (s) can be included in the aerosol generating substrate of the invention. Suitable aerosol generating agents include, but are not limited to: a polyol such as sorbitol, glycerol, and glycols such as propylene glycol or triethylene glycol; a non-polyol such as monohydric alcohols, high boiling hydrocarbons, acids such as lactic acid, glycerol derivatives, esters such as diacetin, triacetin, triethylene glycol diacetate, triethyl citrate or myristates including ethyl myristate and isopropyl myristate and aliphatic carboxylic acid esters such as methyl stearate, dimethyl dodecanedioate, and dimethyl tetradecanedioate.

In a particular embodiment, the aerosol generating substrate comprises a tobacco component in an amount of 60 to 90% by weight of the tobacco composition, a filler component in an amount of 0 to 20% by weight of the composition of tobacco and an aerosol generating agent in an amount of 10 to 20% by weight of the tobacco composition. The tobacco component may comprise paper reconstituted tobacco in an amount of 70 to 100% by weight of the tobacco component.

The aerosol generating device comprises at least one heat source arranged to heat, but not burn, the aerosol generating substrate in use. In use, the at least one heat source has a heating profile. As used herein, "heating profile" refers to the variation in heat energy emitted from a heat source over time. The heat source is used to provide heat to the aerosol generating substrate, to generate an aerosol. Heating of the aerosol generating substrate by the heat source results in the temperature profile of the aerosol generating substrate. As used herein, "temperature profile" refers to the temperature variation of a material over time. It follows that the temperature profile of the aerosol generating substrate is derived from the heating profile of the heat source and the insulating property of any intermediate space between the heat source and the substrate (including when that space is filled with material). or other components).

For the avoidance of doubt, the variation in the temperature of a substrate, and therefore the temperature profile of the substrate, depends on the heat received by the substrate (either from a heat source in a device or otherwise). . It is a product of the heat energy received by the substrate and the heat capacity of the substrate. It follows that the composition of a substrate can affect its ability to absorb heat energy; that is, the heat capacity of the substrate can vary with the composition, thus affecting the temperature profile of the substrate (more heat energy may be required to change the temperature of the substrate). It also depends on the efficiency of thermal conduction from a heat source to the substrate: the further a substrate is from the heat source through the air, or the more insulation there is between the substrate and a heat source, the more heat energy it must be generated by the heat source to change the temperature of the substrate.

On the contrary, the heating profile of a heat source is the result of the variation of the energy generated by the heat source over time. It does not depend on the composition or configuration of the heat source. Rather, it is an absolute measure of the amount of energy generated from a heat source, which in turn can be experienced by a substrate. This experienced energy can cause a temperature change in the substrate, thus affecting the temperature profile of the substrate. However, although it is possible to define the heating profile of a heat source with reference to the heat energy output over time, it may be appropriate to describe a heating profile with reference to the temperature measured at the heat source at the long of the time.

As used herein, "puff" refers to a single inhalation by the user of the aerosol generated by the aerosol generating device.

"Operating temperature" as used herein in relation to a portion of an aerosol generating substrate refers to any temperature of the portion that is within a temperature range that is sufficient for a desired amount to be generated. of aerosol from that portion.

"Operating temperature", as used herein in relation to a heat source, means refers to any heat source temperature that is within a temperature range that is sufficient to generate a desired amount of aerosol from the aerosol generating substrate without burning the substrate. An exemplary range of operating temperatures for the heat source in accordance with the present invention could be 150 ° C to 250 ° C.

"Operating energy output", as used herein, refers to any quantity of heat energy emission from a heat source that is within a range of heat energy quantities that is sufficient to start. to generate a desired amount of aerosol from the aerosol generating substrate without burning the substrate.

The procedure as described herein is intended to reflect a single session of use, that is, a single period of use of the aerosol generating device by a user inhaling a generated aerosol, until the aerosol generating substrate is depleted (the point at which the total particulate matter yield (mg) in each puff would be considered unacceptably low by a user). The session will last for a plurality of puffs. This session can last from 2 to 5 minutes, or from 3 to 4.5 minutes, or from 3.5 to 4.5 minutes, or suitably 4 minutes. The user initiates a session by operating a button or a switch on the device, which causes at least one heat source to start emitting heat energy.

The temperature of each of the aerosol generating substrate portions is preferably an elevated temperature for an extended period during a session. As used herein, "elevated temperature" refers to a temperature greater than 50 ° C, or greater than 100 ° C, or greater than 150 ° C. As used herein, "extended period" refers to a period of time with a duration of a plurality of puffs, which is equal to or less than the duration of the session. For example, an extended period can be a period of time greater than 30 seconds, 50 seconds, 100 seconds, 150 seconds, or 200 seconds. A long period can also be defined in reference to tows: a long period can be a period of time longer than 2 or 5 or 8 or 10 tokes. In particular, the temperature of each portion of the aerosol generating substrate is preferably an elevated temperature for an extended period with a duration of at least 25%, 50% or 75% of the session. In a further embodiment, once a portion of the aerosol generating substrate has an elevated temperature in the session, it remains at an elevated temperature for the remainder of the session.

In some embodiments, the temperature profiles of the aerosol generating substrate portions differ in the rate of temperature change. That is, the temperatures of the portions can begin to rise at the same time and reach substantially the same temperature, but reach substantially the same temperature at different times. For example, the temperatures of both the first and second portions of the aerosol generating substrate may begin to rise at the beginning of the session, but the first portion may reach an operating temperature relatively quickly, and the second portion may reach said temperature relatively slowly, after the first portion. That is, the magnitude of the change in temperature over time may be greater for the first portion than for the second in a part of the session.

Setting the first portion of the aerosol generating substrate to reach an operating temperature quickly and the second portion to reach an operating temperature more gradually can mean that the aerosol is delivered to the user quickly, while also maintaining longevity of use. As the aerosol begins to be generated from the first portion of the aerosol generating substrate, the constituents begin to be depleted from that portion of the substrate. Gradually increasing the temperature of the second portion allows more aerosol to be introduced to maintain a constant supply of aerosol to the user.

In other embodiments, the temperature profiles of the aerosol generating substrate portions may differ from the target temperature. That is, the portions may reach a target temperature at approximately the same time and / or at approximately the same rate, but the target temperatures of the portions are not the same. For example, the temperatures of both the first and second portions of the aerosol-generating substrate may begin to increase at the same rate at the beginning of the session, but the first portion of the aerosol-generating substrate may rise to an operating temperature, and the second portion can be raised to a temperature that is lower than the temperature of the first portion. In one embodiment, the second portion is raised to a temperature that is below operating temperature. In another embodiment, the second portion is raised to an operating temperature. In a particular embodiment, in the first part of the session, the first portion reaches an operating temperature, but the second portion reaches an elevated temperature that is below the operating temperature.

In additional embodiments, the temperature profiles of the aerosol generating substrate portions may differ in both the rate of temperature change and the target temperature. For example, the temperature of the first portion can be raised to an operating temperature relatively quickly, and the second portion can be raised to an elevated temperature that is lower than the temperature of the first portion relatively slowly (the magnitude of the change in temperature over time in the first serving is smaller than that of the first serving for part of the session).

In still other embodiments, where the temperature profiles of the portions differ in the rate of temperature change, or differ in the target temperature, or both, the temperature profiles of the portions may also differ in the onset time. For example, the temperature of the portions can also begin to rise at different times: the temperature profiles can be "staggered" in time. In one embodiment, the temperature of the first portion may begin to rise at the beginning of the session, but the temperature of the second portion may begin to rise only after a period of time has elapsed from the start of the session.

There may be a plurality of discernible stages in the temperature profile of a portion of the aerosol generating substrate. For example, in a specific example, at the beginning of the session, the first portion of the aerosol generating substrate can quickly reach a prescribed operating temperature and remain at that temperature for an extended period. Later in the session, the temperature of the first serving may drop to a second prescribed temperature and remain at that temperature for an extended period. The second temperature is an elevated temperature and may or may not be an operating temperature. In another specific example, at the beginning of the session, the second portion of the aerosol generating substrate may raise its temperature to a first temperature very slowly, or not rise at all. Later in the session, the temperature of the second serving can rise rapidly to a second prescribed temperature and remain at that temperature for an extended period. The second temperature may or may not be an operating temperature. In an even later part of the session, the temperature of the second serving can rise rapidly to a third prescribed temperature and remain at that temperature for an extended period. The third temperature is an operating temperature.

In some embodiments, the heat source can be an electrical heating medium. In some embodiments, the electrical heating means is an electrically resistive heating element.

By "electrically resistive heating element" is meant that by applying a current to the element, the resistance in the element transduces electrical energy to thermal energy that heats the aerosol generating substrate. The heating element can be in the form of resistive wire, mesh, coil, and / or a plurality of wires. In some embodiments, the heat source can be a thin film heater.

The heating element can comprise a metal or a metal alloy. Metals are excellent conductors of electricity and heat energy. Suitable metals include, but are not limited to: copper, aluminum, platinum, tungsten, gold, silver, and titanium. Suitable metal alloys include, but are not limited to: nichrome and stainless steel.

In one embodiment, the heat source can be a material that can be heated by penetration with a varying magnetic field, that is, the aerosol generating substrate can be heated by induction heating. In this embodiment, the device may comprise an electromagnet and a device for passing a variable electrical current, such as an alternating current, through the electromagnet. When the electromagnet and the heat source are relatively suitably positioned so that the resulting variable magnetic field produced by the electromagnet penetrates the heat source, one or more eddy currents are generated within the heat source. The heat source has a resistance to the flow of electrical currents, so when such eddy currents are generated in the object, their flow against the electrical resistance of the object causes the object to heat up. An object that can be inductively heated is known as a susceptor. The heat source can be a susceptor.

The use of electrical resistance heating systems is advantageous because the rate of heat generation is easier to control and lower levels of heat are easier to generate, compared to using combustion to generate heat. Therefore, the use of electrical heating systems allows greater control over the generation of an aerosol from a tobacco composition. The use of induction heating systems can also be advantageous: the magnitude of the varying magnetic field can be easily controlled by controlling the electromagnet. Furthermore, since induction heating does not require a physical connection to be provided between the source of the variable magnetic field and the heat source, the freedom of design and control over the heating profile can be greater and the cost can be lower.

The aerosol generating device may comprise a power source for providing power to the at least one heat source. Generally, this will be an electrical power source to provide electrical power to the at least one heat source. In an exemplary embodiment, the device further comprises a controller for controlling the supply of electrical power from the electrical power source to the at least one heat source. In such embodiments, it is possible to control the heating profile of the heat source by controlling the energy supplied to the heat source over time. By controlling the heating profile of the heat source, it is possible to control the temperature profile of the aerosol generating substrate, thereby controlling the aerosol output of the aerosol generating device in use.

To precisely control the heat output of heat sources, the device may comprise at least one temperature sensor. The sensor can be arranged near or on the heat source, or near or on the aerosol generating substrate. Suitable temperature sensors include thermocouples, thermopiles, or resistance temperature detectors (RTDs, also called resistance thermometers). In a particular embodiment, the device comprises at least one RTD. Temperature data measured by the temperature sensor can be communicated to a controller. Additionally, it can communicate to the controller when a heat source has reached a prescribed temperature, so that the controller can change the power supply accordingly.

When the device comprises at least one electrically resistive heating element, a source of electrical energy, a controller and at least one temperature source, the heating profile of the at least one heating element during the session is predefined by the programming of the controller. . In a particular embodiment, the control of the energy supplied to the at least one heating element does not depend on the detection of when a puff occurs. That is, the controller does not activate, deactivate, or otherwise significantly change control of a heating element in response to a puff sensor; rather, the warm-up profiles are predefined according to times in the session. For example, the controller can be programmed to provide a different amount of energy to the at least one heat source after a predefined period of time has elapsed from the start of the session by the user, thereby changing the output of heat at that time.

By controlling the temperature profiles of the first and second portions of the aerosol generating substrate so that the temperature profile of the first portion is different from that of the second in use, it is possible to control the so-called "puff profile" during use of the device. aerosol generator. In particular, it is possible to provide a substantially constant puff profile during use of the aerosol generating device. As used herein, "puff profile" or "puff profile per puff" refers to the amount of total particulate matter yield (mg) in each puff as the user consumes the aerosol.

One method of controlling the temperature profiles of the first and second portions of the aerosol generating substrate so that the temperature profiles of the portions are different in use is to use an aerosol generating device comprising two heat sources: a first heat source and a second heat source. When such a device is used with an aerosol generating substrate comprising first and second portions, the first heat source is arranged to heat, but not burn, the first portion of the aerosol generating substrate, and the second heat source is arranged to heating, but not burning, the second portion of the aerosol generating substrate.

In other embodiments, the device can comprise more than two heat sources. For example, the device can comprise three, four, five, or more than five heat sources. In such examples, the aerosol substrate used with the device will comprise at least three, four, five, or more than five portions, as appropriate. There may be a greater number of aerosol generating substrate portions than there are heat sources. In a preferred embodiment, the device comprises precisely two heat sources.

In a further embodiment, during the step of heating the aerosol generating substrate, the heating profile of the first heat source may be different from the heating profile of the second heat source. In the configuration described above, the temperature profiles of the first and second portions of the aerosol generating substrate are derived from the heating profiles of the first and second heat sources, respectively. Therefore, different heating profiles of the first and second heat sources will result in different temperature profiles of the first and second portions of the aerosol generating substrate.

The first and second heat sources can be controlled independently; that is, the first heat source can be controlled separately from the second heat source. In such an embodiment, the device may comprise a power source and a controller that can independently provide power to each of the heat sources. When the power source is an electrical power source, the controller can control the electrical power supply from the electrical power source to the first heat source independently of the electrical power supply from the electrical power source to the second heat source. hot. By controlling the energy supplied to each of the heat sources in use, the heating profiles of the heat sources can be controlled, thereby providing an aerosol generating substrate with first and second portions having more than one temperature profile. .

The first and second heat sources can be portions of a single heating element that are capable of different heating profiles. However, preferably, the first and second heat sources are physically separate units. In the case that the heat sources are electrically resistive heating elements, the heating elements can be supplied with separate electrical currents; that is, the heating elements may not be part of the same electrical circuit.

Using two heat sources, it is possible to precisely control the temperature profiles of the first and second portions of the aerosol generating substrate by controlling the heating profiles of each of the heat sources. hot. The control of the heating profiles of the heat sources, in turn, controls the temperature profiles of the portions of the aerosol generating substrate, since the temperature profiles are derived from the heating profiles of the heat sources and the insulating property of the interspace between heat sources and the substrate.

Although the heating profiles of the heat sources induce the temperature profiles of the aerosol generating substrate portions, the heating profiles and the temperature profiles may not correspond exactly. For example: there may be "drain" in the form of heat energy conduction from one portion of the aerosol generating substrate to another; there may be variations in the conduction of heat energy from heat sources to the substrate; There may be a lag between the change in the temperature profile of the aerosol generating substrate and the change in the heating profile of the heat sources, depending on the heat capacity of the substrate.

In embodiments in which the device comprises a controller, the controller can be programmed to control the heating profiles of the heat sources, such that the heating profiles of the heat sources induce prescribed temperature profiles in the first and second second portions of the aerosol generating substrate. For example, the controller can be programmed to control the current supplied to the heat sources so that the heat profiles of the heat sources (and thus the induced temperature profiles of the first and second portions of the generator substrate aerosol) differ in the rate of temperature change, in the target temperature, in the start time, or in any combination thereof. In particular, the controller may be programmed to control the heat profiles of the heat sources to induce any of the temperature profiles of the portions of the aerosol generating substrate specifically described above.

In a particular embodiment where the heat sources are electrically resistive heating elements, a current can be supplied to the first heat source before supplying a current to the second heat source. The second heat source can be "timed" to generate more aerosol from the substrate after the first heat source has started to generate aerosol from the substrate.

Although the heating profiles of heat sources may be staggered, they invariably overlap. That is, when there are a plurality of heat sources, there will be at least one period of time in the session in which more than one heat source is supplying heat energy to the aerosol generating substrate. In one example, when there are two heat sources, there will be at least one period of time in the session in which both the first and second heat sources supply heat energy to the aerosol generating substrate. In particular, when each heat source is an electrically resistive heating element configured to receive a current from an electrical power source controlled by a controller, there will be at least one period of time in the session in which both the first and the second The second heat source is supplying them with a current.

In some embodiments, the first heat source (and consequently the first portion of the aerosol-generating substrate) is arranged closer to the buccal end of the device than the second heat source (and, consequently, the second portion of the aerosol generating substrate). In a particular embodiment, the first heat source that is arranged closer to the mouth end than the second heat source begins to emit heat energy and, therefore, heats the first portion of the aerosol-generating substrate before the second heat source begins to emit heat energy and thereby heat up the second portion.

Each of the heat sources preferably emits heat energy for an extended period during a session. In particular, each of the heat sources emits heat energy for a prolonged period lasting at least 25%, 50% or 75% of the session. In one embodiment, once each heat source has started to emit heat energy in the session, each heat source continues to emit heat energy until the end of the session, when the aerosol generating substrate is depleted. In other words, where each heat source is an electrically resistive heating element configured to receive a current from an electrical power source controlled by a controller, once each source has begun to receive a current from the electrical power source , it will continue to be supplied with a current until the end of the session, when the aerosol generating substrate is depleted.

Emitting heat for an extended period may mean that the device provides substantially constant aerosol formation without the need to heat portions of the aerosol-generating substrate to a very high temperature, or without the need for the heat source to be very hot. This can help prevent overheating or charring of the aerosol generating substrate. For example, in some embodiments, the temperature of a heat source disposed within the aerosol generating device does not exceed 240 ° C when in use. This ensures that the tobacco does not overheat.

Another aspect of the present invention is the device used to generate the aerosol. In one embodiment, the aerosol generating device has a substrate or heating chamber having first and second heating zones. The heating chamber is generally in the form of a hollow cylindrical tube, into which the aerosol generating substrate for heating in use is inserted. The chamber is configured so that, when the substrate is inserted into the cavity, the first and second heating zones correspond to the first and second heating zones. second portions of the aerosol generating substrate, respectively. In a particular embodiment, the heating zones are longitudinally aligned along the heating chamber.

The device further comprises at least one heat source. In use, the first and second heating zones transfer heat energy from the at least one heat source to the first and second portions of the aerosol generating substrate, respectively. In some embodiments, the device comprises a first heat source and a second heat source. In said embodiments, the first and second heating zones correspond to the first and second heat sources.

Preferably, the first and second heating zones transfer heat energy to the outer surface of the aerosol generating substrate. That is, preferably neither the at least one heat source nor the first and second heating zones are disposed within the aerosol generating substrate in use. This can allow the use of a disposable and / or removable aerosol generating substrate particularly easily, with the aerosol generating device.

In other embodiments, the device can comprise more than two heating zones. For example, the device may comprise three, four, five, or more than five heating zones. In these examples, the device can comprise any number of heat sources, as appropriate. There may be a greater number of heating zones than there are heat sources.

The at least one heat source can be annular or at least partially annular. In one embodiment, the heating element can be a thin film heater. In another embodiment, when the heat source is annular, the aerosol generating substrate is in the shape of a rod. Preferably, the aerosol generating substrate is coaxially within the ring of the heat source in use, especially when the aerosol generating substrate is in the shape of a rod.

In a preferred embodiment, the aerosol generating device comprises precisely two heat sources, arranged longitudinally along the heating chamber. Figure 1 is a cross section of the heating chamber when the substrate is arranged in the chamber. The aerosol generating device comprises precisely two heat sources 102 and 104, arranged longitudinally along the heating chamber 100. In particular, the first heat source 102 is arranged closer to the buccal end 106 than the second heat source 104. The second heat source 104 is disposed closer to the distal end 108 than the first heat source 102. The aerosol generating substrate 200 comprises a first portion 202 and a second portion 204. In use, the first heat source 104 supplies heat energy to first portion 202 before second heat source 104 supplies heat energy to second portion 204.

Another method of controlling the temperature profiles of the first and second portions of the aerosol generating substrate, which can be used in conjunction with, or as an alternative to, a plurality of heat sources with different heating profiles as discussed above, is the use of thermally insulating materials or components. In some embodiments, a thermally insulating material is disposed between the at least one heat source and the first and second heating zones, thereby at least partially inhibiting heat transfer from the at least one heat source to the substrate. aerosol generator in use. The insulating material or component is configured differently for the first and second heating zones, such that, if substantially the same amount of heat energy is emitted from the at least one heat source in the direction of both heating zones, The first heating zone would not, however, transfer the same amount of heat energy to the first portion of the aerosol-forming portion that the second heating zone would transfer to the second portion of the aerosol-generating substrate, so the profiles temperature of the portions would differ from each other. An example of such a configuration could be that an insulating material is arranged between the at least one heat source and the first heating zone, but there is no insulating material between the at least one heat source and the second heating zone.

In a particular embodiment, the first and second portions of the aerosol generating substrate are heated by a single heat source. That is, the different temperature profiles of the first and second portions are derived from the configuration of the insulating material alone.

Exemplary insulating materials include aerogels, sol-gels, or ceramics. For example, the insulating material can comprise glass, silica gel, calcium sulfate fibers, or carbon filaments. The insulating component may be a vacuum insulating layer, a layer that is bounded by a material that provides an internal region that is evacuated under low pressure.

Example

In an aerosol generating device comprising:

a tobacco rod comprising first and second portions;

a first and a second electrically resistive heating element corresponding to the portions respective of the rod;

a source of electrical energy;

a plurality of RTDs; and

a controller for controlling the power supplied to the first and second resistive heating elements;

the controller was programmed to do the following:

- When the device is turned on, provide power to the first electrically resistive heating element to heat the element to a temperature of 240 ° C immediately; once the element reaches 240 ° C, keep it at that temperature;

- 75 seconds after turning on the device, provide power to the second electrically resistive heating element to heat the element to a temperature of 160 ° C; once the element reaches 160 ° C, keep it at that temperature;

- 135 seconds after turning on the device, providing power to the second electrically resistive heating element to heat the element to a temperature of 240 ° C; once the element reaches 240 ° C, keep it at that temperature;

- 145 seconds after turning on the device, lower the temperature of the first electrically resistive heating element to 135 ° C.

- 280 seconds after turning on the device, turn it off.

Figure 2 shows a heater trace of the two heater elements as programmed. Figure 3 shows a temperature plot of the heating elements recorded by the RTDs corresponding to the two heating elements. This second plot takes into account the time it takes for the heating elements to reach the prescribed temperature and the temperature rise in the second portion of the aerosol generating substrate even though only the first heating element heats the first portion of the substrate.

The various embodiments described herein are presented solely to aid in understanding and teaching the claimed features. These embodiments are provided as a representative sample of embodiments only and are not exhaustive and / or exclusive. It should be understood that the advantages, embodiments, examples, functions, features, structures and / or other aspects described herein are not to be construed as limitations on the scope of the invention as defined in the claims or limitations in equivalents to those claims, and that other embodiments can be used and modifications made without departing from the scope of the claimed invention. Various embodiments of the invention may suitably comprise, consist or consist essentially of appropriate combinations of the disclosed elements, components, features, parts, steps, means, etc., other than those specifically described herein. In addition, this disclosure may include other inventions not currently claimed, but which may be claimed in the future.

Claims (15)

1. A method of generating aerosol from an aerosol generating substrate (200) using an aerosol generating device with at least one heat source (102, 104) arranged to heat, but not burn, the aerosol generating substrate (200) in use; wherein the aerosol generating substrate (200) comprises first and second portions (202, 204) having substantially the same composition, and / or wherein the aerosol generating substrate (200) comprises first and second portions (202, 204) and there is no physical separation between the portions; the procedure comprising the stages of: heating the aerosol generating substrate (200) in the aerosol generating device for a period of time corresponding to one session of use, such that a temperature profile of the first portion (202) of the aerosol generating substrate (200) during heating is different from a temperature profile of the second portion (204) of the aerosol generating substrate (200); characterized by what During a first part of the session, the first portion (202) of the aerosol generating substrate (200) reaches a prescribed operating temperature and remains at that temperature for an extended period, and the second portion (204) reaches a first temperature that is lower than the temperature of the first portion (202), with the first portion (202) reaching the prescribed operating temperature faster than the second portion (204) reaching the first temperature; During a second part of the session, the second portion (204) is raised to a second prescribed temperature and remains at that temperature for an extended period; and During one third of the session, the second portion (204) is raised to a third prescribed temperature and remains at that temperature for an extended period, the third temperature being an operating temperature. A method according to claim 1, wherein the heating lasts for at least 2 minutes, and the temperature of each of the first and second portions (202, 204) of the aerosol generating substrate (200) is greater than 100 ° C for at least half the duration of the heating. A method according to any of claims 1 to 2, wherein the device comprises: a first heat source (102) arranged to heat, but not burn, the first portion (202) of the aerosol generating substrate ( 200) in use; and a second heat source (104) arranged to heat, but not burn, the second portion (204) of the aerosol generating substrate (200) in use. A method according to claim 3, wherein during said heating, the heating profile of the first heat source (102) is different from the heating profile of the second heat source (104). 5. A method according to any of claims 3 to 4, wherein the first and second heat sources (102, 104) are independently controllable. A method according to any one of claims 3 to 5, wherein the first heat source (102) begins to heat the aerosol generating substrate (200) before the second heat source (104). A method according to any of claims 1 to 6, wherein the device has a buccal end (106) and a distal end (108), and the first portion (202) of the aerosol generating substrate (200) It is disposed closer to the buccal end (106) of the device than the second portion (204) of the aerosol generating substrate (200). A method according to any of claims 1 to 7, wherein once the at least one or each heat source (102, 104) has begun to heat the aerosol generating substrate, said heat source ( 102, 104) continues to heat the aerosol generating substrate until the end of the wearing session. A method according to any of claims 1 to 8, wherein the aerosol generating substrate (200) comprises a tobacco component. A method according to any one of claims 1 to 9, wherein the aerosol generating device is a tobacco warming product. A method according to any of claims 1 to 10, wherein the aerosol generating substrate (200) comprises a tobacco component in an amount of 60 to 90% by weight of the aerosol generating substrate (200), a filler in an amount of 0 to 20% by weight of the aerosol generating substrate (200), and an aerosol generating agent in an amount of 10 to 20% by weight of the tobacco composition. 12. A process according to any of claims 1 and 11, wherein the temperature of the at least one heat source or each of the heat sources does not exceed 240 ° C. A method according to any one of claims 1 to 12, wherein the device comprises a power source for providing power to the at least one heat source (102, 104) and optionally the at least one source. Heat (102, 104) is a thin film heater. A method according to any of claims 1 to 13, wherein the aerosol generating device provides a substantially constant puff profile from the aerosol generating substrate (200). 15. An aerosol generating device comprising: a heating chamber (100) having first and second heating zones (102, 104) arranged so that, when an aerosol generating substrate (200) comprising first and second portions (202, 204) is disposed within the heating chamber (100) of the device, said first and second heating zones (102, 104) are arranged to heat, but not burn, the first and second portions (202, 204) of the aerosol generating substrate ( 200) respectively; wherein the device comprises a controller that is configured so that, in use, the heating profile of the first heating zone (102) is different from the heating profile of the second heating zone (104) for a corresponding period of time to a session of use, so that: During a first part of the session, the first portion (202) of the aerosol generating substrate (200) reaches a prescribed operating temperature and remains at that temperature for an extended period, and the second portion (204) reaches a first temperature that is lower than the temperature of the first portion (202), with the first portion (202) reaching the prescribed operating temperature faster than the second portion (204) reaching the first temperature; During a second part of the session, the second portion (204) is raised to a second prescribed temperature and remains at that temperature for an extended period; and During one third of the session, the second portion (204) is raised to a third prescribed temperature and remains at that temperature for an extended period, the third temperature being an operating temperature.